Do we have a ghost cat in Brambly Cottage ?

We have often said yes we do.We have two cats of our own and yet there have been times where we felt a cat jump upon our bed yet no cat was there!We have seen a cat jump on the windowsill yet n0 cat was there!I have felt a cat purring and yet no cat was there!The no cat by the way is a black cat.We do not have a black cat although throughout my childhood the much loved family cat was black( Sambo) and neil also had a cat as an adult named Black cat (very imaginative in his family!)
Anyway we have often joked about it but sometimes its an unsettling thought.
Well last night in our office Neil was mucking about taking pics of nothing a few he took were from inside our office into the dark loungeroom hall.Now the first has a large orb close to the ground (perhaps cat height) and the next a few seconds later is empty.This is not dust its not reflection.IS IT OUR GHOST CAT ? What do you think ?